Acute cadmium chloride administration induces hepatic and renal CYP2A5 mRNA, protein and activity in the mouse: involvement of transcription factor NRF2

Modulation of the cytochrome P450 (CYP) monooxygenase system by cadmium was investigated in male, adult DBA/2J mice treated with a single dose (16 mumol/kg body weight, i.p.) of cadmium chloride (CdCl2). Total CYP content of liver and kidney microsomes decreased maximally (56% and 85%, respectively) 24 and 18 h, respectively, after CdCl2 treatment. Progressive increases of hepatic coumarin 7-hydroxylase (COH) activity; indicative of CYP2A5 activity, relative to the total CYP content were seen at 8 h (2-fold), 12 h (3-fold), 18 h (12-fold), and 24 h (15-fold). Similar changes were seen in the kidney. Liver and kidney CYP2A5 mRNA levels increased maximally 12 and 4 h after treatment and decreased to almost half 6 h later. In contrast, kidney and liver CYP2A5 protein levels increased maximally at 18 and 24 h. The CYP2A5 mRNA levels in the kidney and liver increased after Cd treatment in Nrf2 +/+ but not in Nrf2 -/- mouse. This study demonstrates that hepatic and kidney CYP2A5 is upregulated by cadmium with a somewhat faster response in the kidney than the liver. The strong upregulation of the CYP2A5 both at mRNA and enzyme activity levels, with a simultaneous decrease in the total CYP concentration suggest an unusual mode of regulation of CYP2A5 in response to cadmium exposure, amongst the CYP enzymes. The observed decrease in the mRNA but not in protein levels after maximal induction may suggest involvement of post-trancriptional mechanisms in the regulation. Upregulation of CYP2A5 by cadmium in the Nrf2 +/+ mice but not in the Nrf2 -/- mice indicates a role for this transcription factor in the regulation. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Endogenous ursodeoxycholic acid and cholic acid in liver disease due to cystic fibrosis

Focal biliary cirrhosis causes significant morbidity and mortality in cystic fibrosis (CF). Although the mechanisms of pathogenesis remain unclear, bile acids have been proposed as potential mediators of liver injury. This study examined bile acid composition in CF and assessed altered bile acid profiles to determine if they are associated with incidence and progression of liver injury in CF-associated liver disease (CFLD). Bile acid composition was determined by gas-liquid chromatography/mass spectrometry in bile, urine, and serum samples from 30 children with CFLD, 15 children with CF but without liver disease (CFnoLD)), and 43 controls. Liver biopsies from 29 CFLD subjects were assessed histologically by grading for fibrosis stage, inflammation, and disruption of the limiting plate. A significantly greater proportion of endogenous biliary ursodeoxycholic acid (UDCA) was demonstrated in CFnoLD subjects vs. both CFLD subjects and controls (2.4- and 2.2-fold, respectively; ANOVA, P = .04), and a 3-4 fold elevation in endogenous serum UDCA concentration was observed in both CFLD subjects and CFnoLD subjects vs. controls (ANOVA, P < .05). In CFLD, there were significant correlations between serum cholic acid and hepatic fibrosis, inflammation, and limiting plate disruption as well as the ratio of serum cholic acid/chenodeoxycholic acid to hepatic fibrosis, inflammation, and limiting plate disruption. In conclusion, elevated endogenous UDCA in CFnoLD suggests a possible protective role against liver injury in these patients. The correlation between both cholic acid and cholic acid/chenodeoxycholic acid levels with histological liver injury and fibrosis progression suggests a potential monitoring role for these bile acids in CFLD.

Prospective case review of a global e-health system for doctors in developing countries

The Swinfen Charitable Trust has managed email consultations for doctors in developing countries since 1999. The process was handled manually for the first three years and then subsequently using an automatic message-handling system. We conducted a prospective review of email consultations between referring doctors and consulting specialists during six months of automatic operation (December 2003 to May 2004). During the study period 125 consultations took place. These concerned a wide range of specialties (e.g. orthopaedics 17%, dermatology 16%, obstetrics and gynaecology 11%, radiology 10%). Of these referrals, 33% (41) were for paediatric cases. Consulting specialists, who were based in five countries, were volunteers. Referring doctors were from 24 hospitals in 12 developing countries. The median time from referral to definitive reply was 1.5 days (interquartile range 0.6-4.9). There was an 85% response rate (n = 106) to a survey concerning the value of the consultation to the referring doctor. All the referring doctors who responded made positive comments about the service and half said that it improved their management of the case. The second-opinion consultation system operated by the Swinfen Charitable Trust represents an example of a global e-health system operated for altruistic, rather than commercial, reasons.

Group A streptococcal vaccine delivery by immunization with a self-adjuvanting M protein-based lipid core peptide construct

Background & objectives: To develop a broad strain coverage GAS vaccine, several strategies have been investigated which included multi-epitope approaches as well as targeting the M protein conserved C-region. These approaches, however, have relied on the use of adjuvants that are toxic for human application. The development of safe and effective adjuvants for human use is a key issue in the development of effective vaccines. In this study, we investigated the lipid polylysine core peptide (LCP) system as a self-adjuvanting GAS vaccine delivery approach. Methods: An LCP-GAS construct was synthesised incorporating multiple copies of a protective peptide epitope (J8) from the conserved carboxy terminal C-repeat region of the M protein. B10.BR mice were immunized parenterally with the LCP-J8 construct, with or without conventional adjuvant, prior to the assessment of immunogenicity and the induction of serum opsonic antibodies. Results: Our data demonstrated immunogenicity of LCP-J8 when coadministered in complete Freund's adjuvant (CFA), or administered in the absence of conventional adjuvant. In both cases, immunization led to the induction of high-titre J8 peptide-specific serum IgG antibody responses, and the induction of heterologous opsonic antibodies that did not cross-react with human heart tissue proteins. Interpretation & conclusion: These data indicated the potential of a novel self-adjuvanting LCP vaccine delivery system incorporating a synthetic GAS M protein C-region peptide immunogen in the induction of broadly protective immune responses, and pointed to the potential application of this system in human vaccine development against infectious diseases.

E-health and the Universitas 21 organization: 2. Telemedicine and underserved populations

Telemedicine activities in underserved communities were reviewed as part of the Universitas 21 (U21) e-health project. A SWOT analysis (strengths, weaknesses, opportunities, threats) was conducted on 12 articles identified in a literature review, supplemented by expertise from U21 members. The analysis showed that threats include the reluctance of populations to use telemedicine services, and a general absence of infrastructure and resources to sustain them. Opportunities centre around potential research, including cost-effectiveness analyses and quantitative assessments of existing telemedicine services. The great strength of telemedicine is that it can improve access to health services among those most in need. However, its greatest weakness is the lack of evidence supporting its clinical and cost advantages relative to traditional services. This represents an important opportunity for research on telemedicine initiatives among underserved populations.

The chemistry and biology of human relaxin-3

A novel member of the human relaxin subclass of the insulin superfamily was recently discovered during a genomics database search and named relaxin-3. Like human relaxin-1 and relaxin-2, relaxin-3 is predicted to consist of a two-chain structure and three disulfide bonds in a disposition identical to that of insulin. To undertake detailed biophysical and biological characterization of the peptide, its chemical synthesis was undertaken. In contrast to human relaxin-1 and relaxin-2, however, relaxin-3 could not be successfully prepared by simple combination of the individual chains, thus necessitating recourse to the use of a regioselective disulfide bond formation strategy. Solid phase synthesis of the separate, selectively S-protected A and B chains followed by their purification and the subsequent stepwise formation of each of the three disulfides led to the successful acquisition of human relaxin-3. Comprehensive chemical characterization confirmed both the correct chain orientation and the integrity of the synthetic product. Relaxin-3 was found to bind to and activate native relaxin receptors in vitro and stimulate water drinking through central relaxin receptors in vivo. Recent studies have demonstrated that relaxin-3 will bind to and activate human LGR7, but not LGR8, in vitro. Secondary structural analysis showed it to adopt a less ordered confirmation than either relaxin-1 or relaxin-2, reflecting the presence in the former of a greater percentage of nonhelical forming amino acids. NMR spectroscopy and simulated annealing calculations were used to determine the three-dimensional structure of relaxin-3 and to identify key structural differences between the human relaxins.

A safety catch linker for Fmoc-based assembly of constrained cyclic peptides

A new safety-catch linker for Fmoc solid-phase peptide synthesis of cyclic peptides is reported. The linear precursors were assembled on a tert-butyl protected catechol derivative using optimized conditions for Fmoc-removal. After activation of the linker using TFA, neutralization of the N-terminal amine induced cyclization with concomitant cleavage from the resin yielding the cyclic peptides in DMF solution. Several constrained cyclic peptides were synthesized in excellent yields and purities. Copyright (c) 2005 European Peptide Society and John Wiley & Sons, Ltd.

Evaluation of the Western Australian Department of Health telehealth project

In 1999, the Department of Health in Western Australia began a telehealth project, which finished in 2004. The 75 videoconferencing sites funded by the project were part of a total state-wide videoconference network of 104 sites. During the period from January 2002 to December 2003, a total of 3266 consultations, case reviews and patient education sessions took place. Clinical use grew to 30% of all telehealth activity. Educational use was approximately 40% (1416 sessions) and management use was about 30% (1031 sessions). The average overhead cost per telehealth session across all regions and usage types was $A192. Meaningful comparisons of the results of the present study with other public health providers were difficult, because many of the available Websites on telehealth were out of date. Despite the successful use of telehealth to deliver clinical services in Western Australia, sustaining the effort in the post-project phase will present significant challenges.

An e-health needs assessment of medical residents in Cameroon

Medical residents from Yaounde I University in Cameroon are required to spend periods of time in rural or remote locations to complete their training. To determine if e-health might lessen their isolation and enhance patient care, a needs assessment of the residents was performed using a brief questionnaire (five items) about the situation in which residents found themselves outside their medical school environment. We gave the questionnaires to 45 residents. Seventeen questionnaires had been returned at the time of the site visit, a response rate of 38%. Most residents indicated that the ability to contact a mentor would have either made them feel more confident (16, or 94%) or altered their handling of recent cases (15, or 88%). All residents had access to a mobile phone, and many (11, or 65%) had used it to contact a medical colleague for guidance. A low-cost and technologically simple telemedicine solution that maximized use of mobile phone capability, provided access to medical and health-care information, and permitted exchange of images would be an appropriate response to the identified needs.